O`Shaughnessy
Key Takeaway
O`Shaughnessy is classified as high hazard in California. It was completed in 1923 and is 103 years old. Its primary use is water supply. High hazard means loss of life is likely if the dam fails — it does not indicate the dam's current condition. Learn more.
Physical Details
| Dam Height | 312 ft (taller than 98.5% in CA) |
| Dam Length | 900 ft |
| Dam Type | Gravity |
| Max Storage | 360.0K acre-ft |
| Surface Area | 1,972 acres |
| Drainage Area | 459 sq mi |
| Year Completed | 1923 (103 years old) |
| NID ID | CA00123 |
Safety Information
Loss of human life is likely if the dam fails.
Hazard potential describes downstream consequences of failure, not the dam's current condition. What does this mean?
Ownership
San Francisco Public Utilities Commission
Local Government
Nearby Dams
Frequently Asked Questions
What is the hazard classification of O`Shaughnessy?
O`Shaughnessy is classified as High Hazard. Loss of human life is likely if the dam fails. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.
Who owns and operates O`Shaughnessy?
O`Shaughnessy is owned by San Francisco Public Utilities Commission (Local Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was O`Shaughnessy built?
O`Shaughnessy was completed in 1923, making it 103 years old. Many U.S. dams were built between the 1930s and 1970s during a period of major infrastructure investment.
What is the primary purpose of O`Shaughnessy?
O`Shaughnessy serves the following purposes: Water Supply, Hydroelectric. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.
How tall is O`Shaughnessy?
O`Shaughnessy has a dam height of 312 ft. Dam height is measured from the natural streambed at the downstream toe to the top of the dam, and may differ from the visible height.
When was O`Shaughnessy last inspected?
O`Shaughnessy was last inspected on May 12, 2022. Inspection dates indicate when a formal review occurred, not the results of that inspection.